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/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* lib/krb5/krb/preauth_encts.c - Encrypted timestamp clpreauth module */
/*
* Copyright 1995, 2003, 2008, 2011 by the Massachusetts Institute of Technology. All
* Rights Reserved.
*
* Export of this software from the United States of America may
* require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. Furthermore if you modify this software you must label
* your software as modified software and not distribute it in such a
* fashion that it might be confused with the original M.I.T. software.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*
*/
#include <k5-int.h>
#include <krb5/clpreauth_plugin.h>
#include "int-proto.h"
static krb5_error_code
encts_prep_questions(krb5_context context, krb5_clpreauth_moddata moddata,
krb5_clpreauth_modreq modreq,
krb5_get_init_creds_opt *opt, krb5_clpreauth_callbacks cb,
krb5_clpreauth_rock rock, krb5_kdc_req *request,
krb5_data *encoded_request_body,
krb5_data *encoded_previous_request,
krb5_pa_data *pa_data)
{
cb->need_as_key(context, rock);
return 0;
}
static krb5_error_code
encts_process(krb5_context context, krb5_clpreauth_moddata moddata,
krb5_clpreauth_modreq modreq, krb5_get_init_creds_opt *opt,
krb5_clpreauth_callbacks cb, krb5_clpreauth_rock rock,
krb5_kdc_req *request, krb5_data *encoded_request_body,
krb5_data *encoded_previous_request, krb5_pa_data *padata,
krb5_prompter_fct prompter, void *prompter_data,
krb5_pa_data ***out_padata)
{
krb5_error_code ret;
krb5_pa_enc_ts pa_enc;
krb5_data *ts = NULL, *enc_ts = NULL;
krb5_enc_data enc_data;
krb5_pa_data **pa = NULL;
krb5_keyblock *as_key;
enc_data.ciphertext = empty_data();
ret = cb->get_as_key(context, rock, &as_key);
if (ret)
goto cleanup;
TRACE_PREAUTH_ENC_TS_KEY_GAK(context, as_key);
/*
* Try and use the timestamp of the preauth request, even if it's
* unauthenticated. We could be fooled into making a preauth response for
* a future time, but that has no security consequences other than the
* KDC's audit logs. If kdc_timesync is not configured, then this will
* just use local time.
*/
ret = cb->get_preauth_time(context, rock, TRUE, &pa_enc.patimestamp,
&pa_enc.pausec);
if (ret)
goto cleanup;
ret = encode_krb5_pa_enc_ts(&pa_enc, &ts);
if (ret)
goto cleanup;
ret = krb5_encrypt_helper(context, as_key, KRB5_KEYUSAGE_AS_REQ_PA_ENC_TS,
ts, &enc_data);
if (ret)
goto cleanup;
TRACE_PREAUTH_ENC_TS(context, pa_enc.patimestamp, pa_enc.pausec,
ts, &enc_data.ciphertext);
ret = encode_krb5_enc_data(&enc_data, &enc_ts);
if (ret)
goto cleanup;
pa = k5calloc(2, sizeof(krb5_pa_data *), &ret);
if (pa == NULL)
goto cleanup;
pa[0] = k5alloc(sizeof(krb5_pa_data), &ret);
if (pa[0] == NULL)
goto cleanup;
pa[0]->magic = KV5M_PA_DATA;
pa[0]->pa_type = KRB5_PADATA_ENC_TIMESTAMP;
pa[0]->length = enc_ts->length;
pa[0]->contents = (krb5_octet *) enc_ts->data;
enc_ts->data = NULL;
pa[1] = NULL;
*out_padata = pa;
pa = NULL;
cleanup:
krb5_free_data(context, ts);
krb5_free_data(context, enc_ts);
free(enc_data.ciphertext.data);
free(pa);
return ret;
}
static krb5_preauthtype encts_pa_types[] = {
KRB5_PADATA_ENC_TIMESTAMP, 0};
krb5_error_code
clpreauth_encrypted_timestamp_initvt(krb5_context context, int maj_ver,
int min_ver, krb5_plugin_vtable vtable)
{
krb5_clpreauth_vtable vt;
if (maj_ver != 1)
return KRB5_PLUGIN_VER_NOTSUPP;
vt = (krb5_clpreauth_vtable)vtable;
vt->name = "encrypted_timestamp";
vt->pa_type_list = encts_pa_types;
vt->prep_questions = encts_prep_questions;
vt->process = encts_process;
return 0;
}
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